Directional panel adapted to control the passage of incident radiation

ABSTRACT

A directionally transmissive optical panel or structure, which is adapted to control the passage therethrough of incident electromagnetic radiation in the visible and invisible spectral regions, is provided. The panel or structure is fabricated with a pair of transparent or translucent plates each having a flat surface and a corrugated surface generally including a series of peaks and valleys extending along the width or horizontal dimension of the respective plates, alternate sections of the corrugated surfaces being fashioned to have an opaque or reflective coating. The corrugated surfaces are maintained in interlocking intimate optical contact.

United States Patent Inventor Sangbong Kim 422 S. Mansfield Ave., LosAngeles, Calil. 90036 Appl. No. 888,463

Filed Dec. 29, I969 Patented Sept. 7, I971 DIRECTIONAL PANEL ADAPTED T0CONTROL THE PASSAGE 0F INCIDENT RADIATION 9 Claims, 6 Drawing Figs.

Int. Cl. G02b 17/00 Field of Search 350/258,

[5 6] Relerences Cited UNITED STATES PATENTS 3,393,034 7/1968 lmai350/260 Primary Examiner-Donald O. Woodiel AuorneyJohn l-loltrichter,Jr.

ABSTRACT: A directionally transmissive optical panel or structure, whichis adapted to control the passage therethrough of incidentelectromagnetic radiation in the visible and invisible spectral regions,is provided. The panel or structure is fabricated with a pair oftransparent or translucent plates each having a flat surface and acorrugated surface generally including a series of peaks and valleysextending along the width or horizontal dimension of the respectiveplates, alternate sections of the corrugated surfaces being fashioned tohave an opaque or reflective coating. The corrugated surfaces aremaintained in interlocking intimate optical contact.

ATENTED SEP 7 197i Fig.2.

lml

4 &

ATTORNEY.

DIRECTIONAL PANEL ADAPTED TO CONTROL THE PASSAGE OF INCIDENT RADIATIONBACKGROUND OF THE INVENTION This invention generally relates tooptically transparent panels which may be used for controlling theamount of electromagnetic radiation, in the visible and infraredspectral regions, that is allowed to be projected into aparticular areaor enclosure, such as a room, while yet permitting sight alongpredetermined lines. i

There are many situations in which the incidence of direct sunlight intoa room is damaging and/or undesirable. For example, in offices and homesthe incidence of direct sunlight can cause discomfort as a result of theheating of the room due to electromagneticradiation in the infraredspectral region. Further, in the case of store show-windows theincidence of electromagnetic radiation in the ultraviolet spectralregion can cause the fading of fabric coloring and the aging and/ordeterioration of certain objects that are subject to extended periods ofexposure.

While such direct exposure to radiation in the infrared and ultravioletspectral regions can be undesirable, radiation in the visible spectralregions is generally desirable for the purpose of illuminating enclosedareas. Additionally, in order for a transparent panel, such as is usedin windows, to serve its generally intended purpose, it must remaintransparent at least along predetermined lines of sight such that aperson is able, for example, to see through the panel.

In other situations requirements may be such that a window should beconstructed to not allow vision along predetermined lines of sight inorder to provide privacy for the occupants of a room or enclosure. Atthe same time the incidence of direct sunlight may be desirable forpurposes of allowing sunbathing or for the resulting heating effects.

There are many devices well known in the prior art that serve to controlthe incidence of direct sunlight into a room or enclosure. Most commonare the numerous varieties of shades and blinds that are adapted to bemounted adjacent a window casing. These shades and blinds are, however,often unsightly, cumbersome and inconvenient from the standpoint ofmaintenance and cleaning.

Also found in the prior art are devices generally comprising panelsformed in a fashion somewhat similar to the instant invention wherein apair of transparent plates having a corrugated surface are fittedtogether to form a single panel having opaque portions internallyextending along one of its primary surface area dimensions. Examples ofsuch prior art devices are presented by US. Pat. Nos. 2,976,759 and3,393,034. These devices are fabricated to have a gap between therespective fitted plates forming the panel and, as a consequence, theoptical phenomenon commonly referred to as parallax is normally present.An additional disadvantage is the care and precision that is required infabricating the corrugated surfaces of such prior art devices for thepurpose of avoiding an excessive amount of optical distortion.

Thus, the purpose of the present invention is to provide a directionallytransmissive optical panel not having the disadvantageous features ofprior art devices.

SUMMARY OF THE INVENTION Briefly, the present invention is adirectionally transmissive panel which may be employed to either preventthe passage of direct electromagnetic radiation in the visible andinvisible spectral regions, such as sunlight, while providing lines ofsight in selected directions, or allow the passage of rays of sunlightincident from selected directions while obstructing predetermined linesof sight.

More particularly, the present invention comprises a pair of transparentor translucent plates each fashioned to have a flat surface andcorrugated surface which includes a series of peaks and valleys formedby a plurality of adjacent flat sections. The corrugations extend alongthe width or horizontal dimension of the respective plates, alternate.ones of the sections having an opaque-or areflective coating whichserves to obstruct the direct passage of incident radiation when thecorrugated surfaces are maintained in an integral interlockingrelationship. i a

Accordingly, itis an object of the present invention to provide a panelfor controllably obstructing the direct transmission of sunlight, whenincident on the panel from predetermined directions, whileproviding anunobstructed line of sight in selected other directions. I

Another object of the present invention is to provide a directionallytransmissive panel ,that will allow true undistorted images tobeprojectedtherethrough.1

A further object of the present inventionis to provide an op tical panelfor controlling the passage of incident radiation in the visible andinvisible spectral regions, which panel is free of parallax. v a

Still another object'of the present inventionis to provide a directionalradiation transmissive panel that is simple to fabricate and easy tomaintain.

DESCRIPTION OF DRA WlNGS Other objects and many of theattendant-advantages of this invention will be more readily appreciatedas the same becomes better understood by reference to the followingdetailed description which is to be considered in connection with theaccompanying drawings in which like-reference symbols designate likeparts throughout the figures thereof and wherein:

'FIG. I is an isometric diagram illustrating: a section of a directionalpanel for controlling the passage of incident radiation in accordancewith the invention;

FIG. 2 is a schematic drawing illustrating an exemplary cross-sectionalside view ofthe invention; and

FIGS. 3-6 are schematic drawings illustrating cross-sec-. tional sideviews of panels respectively having an exemplary variety of corrugatedsurface configurations adapted for different panel uses in accordancewith the invention,

DESCRIPTION OF TI-IEPREFERRED EMBODIMENTS Referring to FIGS. 1 and 2 ofthe drawings, a preferred em-' bodiment of the present inventioncomprises a pair of generally identical plates 10 and 12, asillustrated, the plates 10 and 12 are each adapted to have a flatsurface I4 and a corrugated surface 16 formed by a series of adjacent,flat, alternately identical sections 18 and 20 extending parallel toeach other for the width or along the horizontal dimension of the plates10 and 12. The alternately identical sections 18 and 20 are configuredto form what maybe described as a continuing series of peakslandvalleys. One set of the' alternately identical sections 18 and 20 isadapted to have an opaque or reflective area comprising a coating22extending for the length thereof and covering at least one-half, butpreferably more than one-half, the width thereof.

The opaque or reflective coating 22 may comprise" any of theconventional materials and may be applied, for example, to the sections20, by any of the techniques or methods well known in the prior art. Inthat neither the specific type of coating nor the method of applying thecoating 22 tothe sections 18 or 20 is intended as a part of theinvention, a more detailed description in these regards is not hereinprovided. Preferably, the opaque or reflective coating 22 ischaracterized by the capability of obstructing the passage ofelectromagnetic'radiation-in the visible and invisible spectral regionsranging from identical optical characteristics. In those cases where theinventive panel is intended to allow vision therethrough, the plates Iand 12 should be transparent. However, where only the passage of lighttherethrough is desired, for example, for illumination purposes, thenthe panels may be fabricated with a translucent material.

A directionally transmissive panel, in accordance with the invention, isfabricated by placing and maintaining the corrugated surfaces 16 ininterlocking intimate optical contact. This may be accomplished byeither bonding the respective plates and 12 together with any opticallyfree adhesive that is available in the prior art or by fusing therespective plates 10 and 12 together by employing an appropriate amountof heat and pressure.

As illustrated in FIG. 2, the alternately identical sections 18 and 20may be alternately separated by flat or planar portions 24 and 26 whichmay facilitate the securing of the corrugated surfaces 16 in intimateinterlocking optical contact by avoiding the precision with which sharppeaks generally must be prepared to allow the desired optical contact.

It is to be noted that it is important that the plates 10 and 12 besecured in intimate optical contact such that there not be any parallaxor distortion of light images projected through the panel.

As heretofore discussed the opaque or reflective coatings 22, which areeffectively embedded in the assembled directionally transmissive panel,serves to partially or completely obstruct the passage of light and heatthrough the panel when such light and heat, as typically represented bysunlight, is incident on the panel from directions not parallel to theplane of the opaque or reflective strip formed by the layers of opaqueor reflective material 22. Similarly, the orientation of the opaque orreflective strip can serve to obstruct the passage of light imagesthrough the panel such that only limited lines of sight are available. Amore complete understanding of some'of the applications for the subjectpanel may be obtained by reference to FIGS. 3-6 of the drawings.

Referring to FIG. 3, a cross-sectional view of a panel is shown whereinthe opaque or reflective sections 30 are substantially horizontal.Assuming that the panel is employed as a windowpane with the plate 10serving as the external surface and the plate 12 serving as the internalsurface, sunlight incident on the panel from the general directionindicated by the arrow 32 will be obstructed and thus not allowed topass directly through the panel. Of course some light will be reflectedby the sections 30 and will thus allow illumination of an enclosedinternal area. While direct sunlight is obstructed, it is clear thatlight images will be able to be projected through the panel in thegeneral direction indicated by the arrow 34 provided that the plates 10and 12 are transparent.

In contrast, the opposite effect is obtained by having the opaque orreflective sections 30 oriented at a steep angle as illustrated by FIG.4. Clearly, sunlight projected from the direction indicated by the arrow36 will be projected through the panel while the lines of sight in thegeneral direction indicated by the arrow 38 are obstructed. Thisparticular steep orientation of the opaque sections 30 allow for theprivacy of the occupants of a room while yet permitting sunlight to beprojected through the panel into the room when the panel is employed asa windowpane in a low story room.

FIG. 5 illustrates an orientation of the opaque sections 30 intermediatethat shown by FIGS. 3 and 4, respectively. This intermediate orientationpermits a diminished amount of sunlight to be projected through thepanel when incident from the general direction indicated by the arrow 40and permits a limited view in the general direction indicated by thearrow 42. It is to be understood that the sections 30 may be providedwith any desired orientation dependent upon the application of thepanel.

While the opaque or reflective sections 30 shown in FIGS. 3-5 aresubstantially parallel to each other, there may be certain applicationsfor the panel wherein lines of sight in a number of directions generallyindicated by the arrows 44, 46 and 48 illustrated in F G. 6, is desired.An example of such an application is where the panel is employed as thewindshield of an automobile. To accommodate this requirement, thesections 30 may be situated in varying nonparallel orientations suchthat these different lines of sight are available while direct sunlightis partially obstructed at certain angles of incidence for purposes ofreducing the amount of glare and the degree of blinding that may resultfrom the direct incidence of sunlight on the eyes of an operator of amotor vehicle.

While preferred embodiments of the present invention have been describedhereinabove, it is intended that all matter contained in the abovedescription and shown in the accompanying drawings be interpreted asillustrative and not in a limiting sense and that all modifications,constructions and arrangements which fall within the scope and spirit ofthe present invention may be made.

What is claimed is:

l. A directionally transmissive optical panel comprising a pair ofoptically identical plates each having a first surface that is flat anda second surface that is corrugated, said corrugated surfaces beingformed by a plurality of adjacently oriented elongate planar sectionsextending along one dimension of said plates, alternate ones of saidplanar sections having an opaque area extending for the length of saidsection wherein said second surfaces of said identical plates aresecured in interlocking intimate optical contact.

2. The apparatus defined by claim I wherein said planar sectionsincluded in said corrugated second surfaces are arranged to form aseries of peaks and valleys.

3. The apparatus defined by claim 1 wherein said pair of identicalplates are transparent.

4. The apparatus defined by claim 1 wherein said pair of identicalplates are translucent.

5. The apparatus defined by claim 1 wherein said second surfaces of saidpair of identical plates are secured in interlocking intimate opticalcontact by the application of heat and pressure to said plates.

6. The apparatus defined by claim 1 wherein said second surfaces of saidpair of identical plates are secured in interlocking intimate opticalcontact by an optically free adhesive.

7. The apparatus defined by claim 1 wherein alternate ones of saidplanar sections are oriented in a parallel relationship.

8. The apparatus defined by claim 1 wherein the opaque area of each ofsaid alternate planar sections will obstruct the transmission,therethrough, of electromagnetic radiation in the infrared, visible andultraviolet spectral regions.

9. The apparatus defined by claim 1 wherein said pair of opticallyidentical plates are physically identical.

1. A directionally transmissive optical panel comprising a pair ofoptically identical plates each having a first surface that is flat anda second surface that is corrugated, said corrugated surfaces beingformed by a plurality of adjacently oriented elongate planar sectionsextending along one dimension of said plates, alternate ones of saidplanar sections having an opaque area extending for the length of saidsection wherein said second surfaces of said identical plates aresecured in interlocking intimate optical contact.
 2. The apparatusdefined by claim 1 wherein said planar sections included in saidcorrugated second surfaces are arranged to form a series of peaks andvalleys.
 3. The apparatus defined by claim 1 wherein said pair ofidentical plates are transparent.
 4. The apparatus defined by claim 1wherein said pair of identical plates are translucent.
 5. The apparatusdefined by claim 1 wherein said second surfaces of said pair ofidentical plates are secured in interlocking intimate optical contact bythe application of heat and pressure to said plates.
 6. The apparatusdefined by claim 1 wherein said second surfaces of said pair ofidentical plates are secured in interlocking intimate optical contact byan optically free adhesive.
 7. The apparatus defined by claim 1 whereinalternate ones of said planar sections are oriented in a parallelrelationship.
 8. The apparatus defined by claim 1 wherein the opaquearea of each of said alternate planar sections will obstruct thetransmission, therethrough, of electromagnetic radiation in theinfrared, visible and ultraviolet spectral regions.
 9. The apparatusdefined by claim 1 wherein said pair of optically identical plates arephysically identical.